This happened in Scotland at the Alfred Dunhill Links Championship, which looks to be an event on the European Tour. So this wasn’t just a random country club occurrence. It may have been during a Pro-Am since the story mentions the golfer being partnered with Michael Phelps. The golfer was Paul Casey and he was lining up for an eagle putt when a dog ran onto the green and took the ball!

A spectator stopped the dog and got the ball back. There was no penalty.

A dogs often hanging around major events? Casey said this one showed up at the tee and followed them to the green before it saw an opening on the green to get the ball.